I'm not by any means defending them, but I took a completely clean ghosted machine and ran a test on it and I don't quite get the upset over it.
Here are the steps I went through (along with screenshots):
1) I download the installer
http://ww2.quickbuck.com/moviepass/step1.png
2) I run it and it shows me their terms in a browser
http://ww2.quickbuck.com/moviepass/step2.png
3) I agree to the terms and start watching movies
http://ww2.quickbuck.com/moviepass/step4.png
4) I decide to cancel and follow the link
http://ww2.quickbuck.com/moviepass/step5.png
5) I click once more to complete the cancellation process
http://ww2.quickbuck.com/moviepass/step6.png
6) It's cancelled.
http://ww2.quickbuck.com/moviepass/step7.png
7) Their uninstaller didn't kill the license manager that was running, but after a bit of surfing I saw no ads, I checked a bunch of popular sites and saw no affiliate codes. So I killed it in ctrl-alt-del and then did an add/remove from my program files and there is no trace of it left on my system.
Conclusion
To download the app I had to purposely run it, and then seperately agree to ther terms which were pretty clear. In huge letters it says that if I don't cancel within 3 days I have to pay.
Cancelling my membership took a visit to a web page and two clicks to cancel.
It took me more work to download, install, agree to terms & watch the movie than to cancel the membership.
I guess if you didn't bother to even read the huge "urgent reminder" (see step 2) then it might not make sense, but it seemed more clearly disclosed than even the average cross sale imho.
Maybe I'll start seeing popups soon, but thats my report for now. Will return with more if I have any.